Objective: To investigate the effects of high level hepatitis B virus (HBV) replication on the hepatocytes. QSG-7701 cells.
Methods: Human hepatocytes of the line QSG-7701 were cultured and transfected with the plasmid pUC18-HBV1.2 or pUC18 containing 1.2 full length HBV DNA by the standard calcium phosphate precipitation method. Other QSG-7701 cells were transfected with the plasmid pUC18 as controls. Cell growth curves were drawn for 7 days after transfection. Four 4 days after transfection, HBV DNA in the culture medium was detected by using fluorescence quantitative real-time PCR. Cell apoptosis was detected by using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and electronic microscopy. Differential expressed genes were analyzed by using Oliga signal pathway micro-array.
Results: The curves of cell growth showed that the amount of control QSG-7701 cells increased by (8.3 +/- 1.2) times, significantly faster than the pUC18-HBV1. 2 transfected QSG-7701 cells that increased only by (1.1 +/- 0.2) times (P < 0.01). Four days after transfection, the HBsAg positive rate of the pUC18-HBV1.2 transfected cells was 35.4% +/- 6.7%, and the apoptotic rate was 15.2% +/- 4.3%. The HBV DNA level in the culture supernatant peaked 4 days adder transfection with the maximum value of (5.8 +/- 2.6) x 10(6) copies/ml. Genes related to cell growth and apoptosis, such as CASP3 (2.7981) ,CASP7 (2.2643), 3-Apr (3.5013), CDC2 (0.4380), MAPK6 (0.4447), and MAP3K2 (0.2785), were differentially expressed.
Conclusion: High replicated HBV markedly inhibits the growth of hepatocytes and induces cell apoptosis.